Jessica Portner

Tyler Goark, 14, and Megan Skidmore, 13, are typical students at a fairly representative middle school in a middle-class suburb. For a week last spring, they offered themselves as guides into a territory that few adults can navigate alone—7th grade.

School officials, police, and local leaders in Jefferson County, Colo., worked round the clock last week trying to pick up the emotional pieces of a community torn apart by two students with firearms and an arsenal of explosives.

One-fifth of high school girls in the United States say they have been sexually or physically abused, and 8 percent of teenage girls say they've been forced by a date to have sex against their will, says a new national survey.